Hot blast stove



April 23, 1940. R. CARRIGAN HOT BLAST STOVE Filed Deo. 27, 1939 2 Sheets-Sheet l jme April 23, 1940. R. CARRIGAN HOT BLAST STOVE Filed Dec. 27, 1939 2 Sheets-Sheet 2 VJ fa/enh?? Ear (42E/54N,

i////iqy Patented pr. 23, 1940 UNITED STATES PATENT OFFICE Ho'r BLAST srovE Ray Carrigan, Birmingham, Ala.

Application December 27,'1939, Serial No. 3113203 `a conventional outer steel shell Ilia.

4 Claims.

This invention relates to detailed improvements Iin hot blast stoves of the type described in my earlier patent, No. 1,915,880, dated June 27, 1933. The stoves of the character described in this previous patent include supporting arches of metal which in turnV directly support checker-- brick.

According to the teachings of the present invention, I preferably provide respective inner and outer upright metal supports spanned by metallic arches which in turn support the checkerwork constituting the flues of hot blast stoves; The improved supporting means of the present invention take the form of metal liners which are preferably cast in segmental units.

One set of segmental units is mounted in juxtaposition to `the outer annular wall of the stove, `and the other setI is mounted around the exterior of a wall which denes an inner combustion chamber. The lower ends of the segmental units are preferably imbedded in thev foundation brickwork of the stove, and the upper ends are conveniently held in place by interengagement with notched portions formed at the extremities of the checkerwork-supportng arches. The above and more detailed features of the invention will be fully apparent from the following disclosure when read in connection with the accompanying drawings, in which:

Figure 1 is a longitudinal section of the lower portion of a blast furnace `hot blast stove embodying the present invention.

Figure 2 is a horizontal section thereof, taken approximately on the staggered line II-II of Figure 1.

Figure 3 is a fragmentary detail section taken on line III--III of Figure 2.

Figure 4 is a fragmentary detail section taken on line IV-IV of Figure 2. i

Referring more particularly to the specific einbodiment of the invention herein illustrated, I represents afoundation course of brickwork which supports an outer annular wall I2 and an inner annular wall I4, these walls defining respectively achecker chamber I 6 and a combustion chamber I'I. The structure thus fardescribed is of somewhat conventional form, and is encased in The stove will be equipped with the usual hot blast inlet I8, gas inlet 2U, and a pluralityof ducts 22.

The present invention is directed chiefly to improved means for supporting the checkerbrick constituting the heat exchange element of the furnace, this checker-brick per se being of conventional construction. The checker-brick in (ci. 26a-i9) arches which in turn transmitted their respective static loads directly to the brickwork of the masonry structure. According to the present invention, supporting arch bars for the checkerwork take their bearings on metallic members which have greater compressive strength than the brickwork heretofore used. Thus, by the use of metal members in place of the brckwork, adequate strength is provided, yet a amount of spaceis occupied within the stove. This has the advantage of augmenting heatexchange capacity for a stove of given dimensions.

The objects of this invention are attained by providing an outer series of segmental units 24, each of which comprises an upright web portion 26 and upper and lower flanges 28 and 30, ccnnected by upright flanges 32.

The bottom flanges of the segmental units constitute footing portions which are desirably embedded in the brickwork or foundation portion lll of the stove.

An inner series of segmental units is also provided, as indicated generally at 34, the same being of somewhat similar flange and web construction to that described in connection with the outer units 24.

. Spanning the space between the inner and outer series of segmental units 34 and'24 are a plurality of main supporting arch bars 36. These are preferably formed of cast iron, in order to give adequate strength, and are notched as indicated at 38 and 4I), to intert with the upper extremities of the segmental nunits 24 and34. Thus the units are held in proper spaced relation at the top.

A plurality of obliquely arranged supplemental arched supporting members 42 are so positioned that their inner ends rest on certain of the main arches, and their outer ends rest directly on the tops of certain of the segmental units constituting outer liner 24. A number of other obliquely disposed arch-like supporting bars 44 are so arranged that they span the space between the outer units 24 and the inner units 34.

At that location in the stove where the hot blast conduit I8 and gas conduit 20 are located, a special type of support is provided including an arched portion 46 which straddles the masonry structure in which said openings are formed. At this zone the supports. are provided with i stepped portions 48, as shown in Figure 3. In

this way the arch bars can be conveniently positioned to suit the physical arrangement of the structure occasioned by the necessity of providing the hot blast and gas openings.

The arrangement described provides a means whereby the conventional form of checker-brick 50, constituting the iiues of the hot blast stove, can be effectively supported directly on the metallic arch bars, as indicated at 42 and 44. The arch bars 42 and 44 and also the multiplicity of segmental members which vconstitute the outer and innerannular segmentalsupports' 24 and 34 are alldesirably made of cast iron, which has a lower specific heat ratio and more weight than fire brick. These principles thus give an increase in the rate of heat transfer from the gas to the support and in the reverse cycle from the support to the cold air blast. The structure and arrangement of the parts described are such that the elements can be quickly and easily erected at the time of the initial installation. Moreover, the

'segmental construction of the inner and outer l specific embodiment of the l'invention herein illustrated, it is to be understood that Various modifications may be made by those skilled in the art without departure from the invention dened in lthe appended claims.

I claim:

1,. l Alhot blast stove comprising inner and outer walls .defining respectively a combustion chamber `and. a checker chamber, respective upright metal.r supports arranged around the exterior of said inner wall and around the interior of said outer wall, metal arch bars spanning said upright supports, and checker-brick supported directly on said metal arch bars.

2. A hot blast stove comprising inner and outer Walls defining respectively a combustion chamber and a checker chamber, a series of segmental metal units arranged around the inner face of said outer Wall, a similar series of segmental metal units arranged around the outer face of said inner wall, metal arch bars spanning the space between said two series of units and jointly supported thereby, and checker-brickzsupported directly on said metal arch bars.

3. A hot blast stove comprising inner and outer walls defining respectively a combustion chamber and a checker chamber, respective upright metal supports arranged around the exterior of said inner wall and around the interior of said outer wall, a plurality of main supporting metal arch bars spanning said upright supports, and supplemental metal members in a plane above said main arch bars and disposed obliquely thereto, some of said supplemental members being supported in part directly on the upright support adjacent said outer Wall.

4. A hot blast stove comprising inner and outer walls defining respectively a combustion chamber and a checker chamber, a series of segmental metal units arranged around the inner face of said outer wall, a similar `series of segmental metal units arranged around the outer face of said inner wall, metal arch bars spanning the Vspace between said two series of units and jointly supported thereby, checker-brick supported directly on said arch bars, the bottoms of said segmental units being embedded in a brickwork base, Y

and the said archl bars having notched portions at each end for interengagement with the tops of said units and adapted to hold the latter in 

